Gametrailers.com review the sixaxis evolution game flOw.
Going along with Sony's off base products (LittleBigPlanet), this isn't so much a game but a relaxing experience that you can pick up and play without any stress. A number of players can just swim in at any time, and you can swim out. Or you can simply go have a break and leave it running as an HD Screensaver.
"It's not a game, but a tool to help you wind down from an intense battle in Virtua Fighter 5 or Motorstorm"